8f0b3c69-5233-421a-9429-50659923082d.ppt

asam karboksilat ppt kimia organik

1. CARBOXYLIC
ACID
PRESENTED BY
Prof. Dr. Suyatno, M.Si.
DEPARTMENT OF CHEMISTRY
STATE UNIVERSITY OF SURABAYA
2020

2. INTRODUCTION
A GROUP OF ORGANIC COMPOUND WITH FUNCTIONAL
GROUP : -COOH (CARBOXYL GROUP)
MANY CARBOXYLIC ACID SHOWED IMPORTANT ROLE IN
DAYLAY LIFE

3. Glucoseismetabolizedtopyruvicacid.(S)-(+)-Lacticacidisresponsibleforthe
burningsensationfeltinmusclesduringanaerobicexercise,andalsofoundinsour
milk.Spinachandotherleafygreenvegetablesarerichinoxalicacid.Succinicacid
andcitricacidareimportantintermediatesinthecitricacidcycleinbiological
systems.Citrusfruitsarerichincitricacid;theconcentrationisgreatestinlemons,
lessingrapefruits,andstilllessinoranges.(S)-Malicacidisresponsibleforthe
sharptasteofunripeapplesandpears.Asthefruitripens,theamountofmalic
acidinthefruitdecreasesandtheamountofsugarincreases.Theinverse
relationshipbetweenthelevelsofmalicacidandsugarisimportantforthe
propagationoftheplant:Animalswillnoteatthefruituntilitbecomesripe—at
whichtimeitsseedsarematureenoughtogerminatewhentheyarescattered
about.Prostaglandinsarelocallyactinghormonesthathaveseveraldifferent
physiologicalfunctions,suchasstimulatinginflammation,causinghypertension,
andproducingpainandswelling.

4. NOMENCLATURE
Systematic names for carboxylic acids are derived by counting the
number of carbons in the longest continuous chain that includes the
carboxyl group and replacing the –e ending of the corresponding
alkane by –oic acid.
When substituents are present, their locations are identified by
number; numbering of the carbon chain always begins at the carboxyl
group.
Double bonds in the main chain are signaled by the ending -enoic
acid, and their position is designated by a numerical prefix.
When a carboxyl group is attached to a ring, the parent ring is named
(retaining the final -e) and the suffix –carboxylic acid is added, as
shown in entries 8 and 9.
Compounds with two carboxyl groups, as illustrated by entries 10
through 12, are distinguished by the suffix -dioic acid or –dicarboxylic
acid as appropriate. The final –e in the base name of the alkane is
retained.

5. H
3C
C
H
2
CH
C
H
2
C
OH
OCH
3
1
2
3
4
5
3-methylpentanoic acid
H
2
C
CH
H
2
C
CH
C
OH
O
1
2
3
4
5
2-ethyl-4-methylhexanoic acid
CH
2
H
3C
H
3C
H
3C
6
H
3C
CH
CH
C
OH
OOH
1
2
3
4
2-bromo-3-hydroxybutanoic acid
Br
COOH
OH
H
3C
1
2
3
4
5
6
2-hydroxy-5-methylbenzoic acid EXAMPLES

6. THE OTHER EXAMPLES

7. Give a sistematic IUPAC name for the following compounds:
PROBLEM
a.2-methylpropenoic acid
b.E-2-butenoic acid/ trans-2-butenoic acid
c. Ethanedioic acid
d. 4-methyl benzenecarboxilyc
acid/ 4-methyl benzoic acid

8. STRUCTURE AND BONDING
Additionally, sp2 hybridization of the hydroxyl oxygen allows one of its
unshared electron pairs to be delocalized by orbital overlap with the 
system of the carbonyl group
The structural features of the carboxyl group are most apparent in
formic acid. Formic acid is planar, with one of its carbon–oxygen
bonds shorter than the other, and with bond angles at carbon close to
120°.

9. Lone-pair donation from the hydroxyl oxygen makes the carbonyl
group less electrophilic than that of an aldehyde or ketone.
Carboxylic acids are fairly polar, and simple ones such as acetic acid,
propanoic acid, and benzoic acid have dipole moments in the range
1.7–1.9 D.

10. PHYSICAL PROPERTIES
Themeltingpointsandboilingpointsofcarboxylicacidsarehigher
thanthoseofhydrocarbonsandoxygen-containingorganic
compoundsofcomparablesizeandshapeandIndicatestrong
intermolecularattractiveforces.
A unique hydrogen-bonding arrangement, contributes to these
attractive forces. The hydroxyl group of one carboxylic acid molecule
acts as a proton donor toward the carbonyl oxygen of a second. In a
reciprocal fashion, the hydroxyl proton of the second carboxyl function
interacts with the carbonyl oxygen of the first. The result is that the two
carboxylic acid molecules are held together by two hydrogen bonds. So
efficient is this hydrogen bonding that some carboxylic acids exist as
hydrogen-bonded dimers even in the gas phase.
Mr=70
Mr=72
Mr=74 Mr=74

11. In aqueous solution intermolecular association between
carboxylic acid molecules is replaced by hydrogen bonding to
water. The solubility properties of carboxylic acids are similar
to those of alcohols. Carboxylic acids of four carbon atoms or
fewer are miscible with water in all proportions.

12. ACIDITY OF CARBOXYLIC ACID
Carboxylic acids are the most acidic class of compounds that
contain only carbon, hydrogen,and oxygen. With ionization
constants Ka on the order of 10
-5
(pKa= 5), they are much
stronger acids than water and alcohols.

13. The resonance effect of the carbonyl group
The inductive effect of carbonyl group

14. SUBSTITUENTS AND ACIDS STRENGTH

17. PROBLEM
Which is the stronger acid in each of the following
pairs?

18. SYNTHESIS OF CARBOXYLIC ACID

19. GRIGNARD REACTION

20. HYDROLYSIS OF NITRILE

21. PROBLEM
Explain the steps happened in the following reaction!

22. REACTIONS OF CARBOXYLIC ACID

23. PROBLEM
1.Propose methods for preparing butanoicacid from
each of the following:
(a) 1-Butanol (d) 2-Propanol
(b) Butanal (e) Acetaldehyde
(c) 1-Butene (f) 1-Propanol
2.Givetheproductofthereactionofpentanoicacidwith
eachofthefollowingreagents:
(a)Sodiumhydroxide
(b)Sodiumbicarbonate
(c)Thionylchloride
(d)Phosphorustribromide
(e)Benzylalcohol,sulfuricacid(catalyticamount)
(f)Chlorine,phosphorustribromide(catalyticamount)
(g)Bromine,phosphorustrichloride(catalyticamount)
(h)Productofpart(g)treatedwithsodiumiodideinacetone
(i)Productofpart(g)treatedwithaqueousammonia
(j)Lithiumaluminumhydride,thenhydrolysis
(k)Phenylmagnesiumbromide